Musnad Ahmad 26:708

I read to my father: 'Amr ibn Mujamma' narrated to us, Ibrahim al-Hajari narrated to us, from Abu al-Ahwas, from Abdullah ibn Mas'ud, from the Prophet, peace and blessings of Allah be upon him, who said: "Indeed, the first to institute the *sa'ibah* (sacred camels) and worship idols was Abu Khuza'ah, 'Amr ibn 'Amir; and I have seen him dragging his intestines in the Fire."